Stone retrieval devices are often employed in order to remove a stone from a ureter or kidney. Removal of a stone from a ureter or kidney is a difficult process because the area within which the medical professional works is small and narrow. Often a stone is not located directly in front of the retrieval basket. The location of the stone makes it difficult to retrieve. In an attempt to retrieve the object, the medical professional will attempt to bend the basket, causing the basket to bend-over partially onto itself. This movement will allow one side of the basket to expand and be more open than the opposite side. When the basket is at least partially bent-over on itself, the medical professional will attempt to maneuver the basket so that it encapsulates the object. However, the basket cannot be extended or retracted while bent. Thus, stones that are not directly in front of the device cannot be easily captured.
The medical professional has little control of the basket because the basket cannot be bent while being extended or retracted. Thus, during the interim period between when the basket surrounds the stone and when the basket is retracted, the stone can shift, move, or dislodge, making the capture attempt a failure, causing the medical professional to start the procedure over.